1. Field of the Invention
The present invention relates to an image projection apparatus.
2. Description of the Related Art
Image projection apparatuses have been known that include digital mirror devices (DMDs) serving as image forming elements that modulate light on the basis of image data supplied from personal computers, for example, and image forming units having irradiation units irradiating the image forming elements by light from light sources, and in which the image forming units form images and the images formed by the image forming units are focused on projection planes using projection optical sections.
The image projection apparatuses use halogen lamps, metal halide lamps, or high-pressure mercury lamps as the light sources. These lamps reach a high temperature when emitting light. Japanese Patent Application Laid-open No. 2002-244210 and Japanese Patent Application Laid-open No. 2008-102374 disclose image projection apparatuses. In an example of the image projection apparatuses, ambient air is taken in from an intake port provided to the apparatus by an air supplying unit such as a blower or a fan, the air taken in is supplied to a light source to cool the light source, and air of which the temperature has increased by taking heat from the light source is discharged outside the apparatus via an exhaust port.
An operating unit serving as an input mechanism such as buttons for a user to operate the image projection apparatus is preferably disposed on the upper surface of the image projection apparatus for allowing the user to readily operate the image projection apparatus.
The temperature of the light source reaches up to about 1000° C. even though the light source is cooled by supplied air. As a result, air heated by the light source flows upward by air supplied from an air supplying unit and its ascending air current. In addition, heat from the light source is conducted toward the operating unit by thermal conduction. When the operating unit is disposed above or just above the light source, a problem arises in that air heated by the light source and flowing upward, heat by the thermal conduction, and heat by natural convention collide with the operating unit disposed above or just above the light source and the operating unit is heated by the heated air and the heat, thereby increasing the temperature of the operating unit.
Therefore, there is a need for an image projection apparatus capable of suppressing an increase in the temperature of an operating unit even when the operating unit is disposed above or just above a light source.